Measurement and modeling of complex fluid properties associated with chemical separations, nanoscale processing, and energy production using statistical mechanics, molecular simulation, NMR, and high pressure experiments.

Corrosion and Scale at Extreme High Temperatures and High Pressures - Experiment and Modeling

A challenge of the energy production from the ultra-deepwater is flow assurance issues that result from the extreme temperatures and pressures that are encountered. In this DOE sponsored project, we produce experimental data for corrosion and scale at extreme conditions not previously measured and develop molecular models to describe the corrosion and scale occuring under high temperature and high pressure conditions.

Research Interests 31-JAN-2018

The formation of asphaltene plugs in piping represent a significant problem in oil production and refining. Asphaltenes are a collection of polydisperse molecules consisting mostly of polynuclear aromatics with varying proportions of aliphatic and alicyclic moieties and small amounts of heteroatoms (oxygen, sulfur, vanadium, etc.). Problems in recovery and refining operations associated with asphaltenes are due primarily to their molecular size and their self-aggregation. Hence, a better understanding of asphaltene phase behavior and deposition requires a better understanding of how molecular size and aggregation affect phase behavior and deposition. A similar material to asphaltenes are polynuclear aromatics extracted from pitch. Researchers have shown that these polynuclear aromatics for a meso-phase that can be used to spin inexpensive, high quality carbon fibers. Professor Chapman's group has developed a method to characterize crude oil thermodynamic properties and asphaltene phase behavior using the Statistical Associating Fluid Theory (SAFT). His group is currently developing a wellbore deposition simulator.

Research Interests 31-JAN-2018

Professor Chapman's research group uses tools such as molecular simulation, computer visualization, statistical mechanics, and NMR to discover how material properties and structure depend on molecular forces. Professor Chapman's present research program focuses on polymer solutions and blends, associating fluids, confined fluids, and natural gas hydrates.

Computational Modeling of Soft Materials - Thermodynamics and Structure of Complex Fluids in the Interfacial Region

Prediction of the interaction of complex fluids, (e.g., hydrogen bonding fluids, hydrocarbons, proteins, and polymers) with adsorbing surfaces is essential for the control of many processes of current industrial and scientific interest. These processes include microchannel reactors, catalysis, assembly of nano-materials, bio-sensors, and membrane separations. Professor Chapman's group has developed molecular simulations and density functional theory to predict the thermodynamic properties, structure, and surface forces of associating and non-associating components near hydrophobic and hydrophilic surfaces. The surface forces provided by the density functional theory are key to modeling biochemical processes involving proteins or DNA as well as assembly of nanoscale systems.

Mechanisms and Kinetics of Gas Hydrate Decomposition

Gas hydrates are, quite literally, self-assembled nano-structures formed by the cooperative hydrogen bonding of water molecules to form cages that encapsulate gas molecules. These solid crystalline clathrate structures are significant because they trap vast amounts of natural gas on the ocean floor (notably the Gulf coast) and in permafrost and other geologic deposits. The amount of carbon in gas hydrates is estimated to be more than twice the amount of carbon in all other fossil fuel deposits. Gas hydrates have also been proposed as potentially useful in novel gas separation processes and in transport of natural gas. Gas hydrates are also a problem in their proclivity to plug subsea pipelines from offshore platforms causing economic loss and potentially unsafe conditions. To avoid hydrate plugs, the oil and gas industry spends about 500 millions of dollars annually on inhibitors (e.g., methanol or glycol) or as much as $48 MM to insulate a single subsea pipeline (Exxon).

To accurately model the decomposition and formation processes and to optimize hydrate applications requires the mechanism and dissociation rates of hydrates as well as heat and mass transfer data. In addition, quantifying the effect of porous media on hydrate decomposition kinetics is essential for the production of natural gas from hydrates. Professor Chapman's group combines NMR and molecular simulation with phase equilibria and kinetic studies to provide needed thermodynamic, transport, and kinetic data for hydrate decomposition.

Molecular Thermodynamics of Solvents, Monomers, and Polymers

Polymers with multiple functional groups have been found to possess unique and useful optical, thermal, and mechanical properties. The manufacture of these polymers requires knowledge of their solution properties and phase behavior to optimize the design and operation of reactors and separation units. Professor Chapman's group uses molecular modeling techniques (including molecular simulation and statistical mechanics) to relate knowledge of molecular forces to the thermophysical properties of polymer solutions and blends. The Statistical Associating Fluid Theory (SAFT) equation of state produced from this research is applied by numerous polymer companies throughout the world to model phase behavior in polymer processing.

Research Interests 31-JAN-2018

Density functional theory and molecular simulation are used to study the partitioning and transport of hydrocarbons and water in kerogen related to fracing and energy production.

secondary presenter. "Investigation of Clathrate Hydrate Formation and Decomposition Mechanisms Through Viscosity and NMR Measurements." American Institute of Chemical Engineers National Meeting, San Francisco, CA. (November 2003) With Shuqiang Gao and Waylon House

"Measurement and Prediction of Asphaltene Phase Behavior in Model and Live Oil Using Mono- and Polydisperse SAFT EOS." American Institute of Chemical Engineers Annual Meeting, Indianapolis, Indiana. (November 2002) With P. David Ting and George Hirasaki

"Asphaltene Phase Behavior: Experiment and Modeling using the SAFT Equation of State." American Institute of Chemical Engineers Annual Meeting, Reno, NV. (November 2001) With P. David Ting and George Hirasaki

"Gas Solubility in Alkanes, Alkenes, and Alkanols from a SAFT Based Approach." American Institute of Chemical Engineers Annual Meeting, Reno, NV. (November 2001) With Auleen Ghosh, Ray French, and George Koplos

"Application of an Extended SAFT Equation of State to Phase Equilibria in Polar Polymer Solutions." American Institute of Chemical Engineers National Meeting, Miami Beach. (November 15-20, 1998) With Prasanna K. Jog and Keshawa P. Shukla

"Molecular Thermodynamics of Polymers: Monomers as Molecular Building Blocks." Invited Lecture at the Technical University of Berlin, Germany. (June (1998)) With Prasanna K. Jog and Alejandro J. Garcia-Cuellar

"Plenary Lecture: Extensions and Applications of the SAFT Equation of State to Solvents, Monomers, and Polymers." Presented at the 8th International Conference on Fluid Properties and Phase Equilibria for Product and Process Design, Netherlands. (May (1998)) With with Prasanna K. Jog and Alejandro J. Garcia-Cuellar

"Plenary Lecture: Some Advances in Polyatomic and Associating Fluid Thermodynamics." Presented at the 5th Liblice Conference on the Statistical Mechanics of Liquids, Czech Republic. (June (1998))